1. Field of the Invention
The instant invention pertains to a series of pulsating fluid jets for directing fluids across the exterior surface of a helmet window, wherein the associated helmet is to be used in a dust laden atmosphere and the pulsating fluid jets function to maintain the exterior surface of the window clean of dust and form a reasonably constant flow of liquid across the window exterior surface and a flow or curtain of air thereover so as to maintain maximum visibility by a person wearing the associated helmet.
2. Description of Related Art
Various different forms of helmets and goggles including fluid jet structures for maintaining the exterior surface of a viewing window relatively clean heretofore have been provided. Examples of these previously known devices are disclosed in U.S. Pat. Nos. 1,881,192, 2,971,196, 3,231,897, 3,605,766, 4,150,681 and 4,369,782. However, these previously known devices are not particularly well adapted to function well in a heavily dust laden atmosphere such as that which is encountered by workmen operating dry or wet sand blasting equipment. Further, these previously known devices are not capable of maintaining maximum vision through the associated window while still providing a constant flow of cleaning liquid thereacross.